In this study the effect of varying levels of fenugreek were examined on the plasma lipids of animals pretreated with either a control diet or a high-fat diet for 9 weeks. Although the plasma cholesterol was significantly reduced in both groups, triglyceride levels were only reduced in animals pretreated with the high-fat diet. HDL-cholesterol levels were not significantly altered in and case. In addition, the effect of fenugreek seed powder and some of its extracts were investigated for the determination of the active fraction. Fenugreek seed powder and its extracts at 30% of the animals' diet were observed to greatly affect the plasma lipids when added to animals pretreated with a high-fat. Fenugreek and its extracts reduced the levels of cholesterol, triglyceride and LDL-cholesterol with no effect on the HDL-cholesterol. This selective reduction in LDL-cholesterol results in the improvement of the ratio of HDL-cholesterol to LDL-cholesterol which is beneficial in the prevention of atherosclerosis. In addition, the ratio of total cholesterol to HDL-cholesterol was reduced. This hypolipidaemic effect of fenugreek was associated with the defatted fraction of the seed powder, and among the extracts analysed, the crude saponin extract was the most effective fraction with respect to the fenugreek seeds. The improvement of the plasma lipid profile by fenugreek treatment further supports the use of fenugreek seeds as a hypolipidaemic agent in the improvement of lipid disorders.